Gut Series: The Stomach

To continue our journey through the GI tract, today we’ll look at digestion in the stomach.

Once the esophagus has moved food into the stomach, the stomach begins to contract in order to move food from the upper part of the stomach to the lower part. Also, the stomach secretes a number of gastric “juices” that help break down the food you have eaten. These include hydrochloric acid (stomach acid), digestive enzymes such as protease and lipase that help break down proteins and fats, intrinsic factor (a substance that helps the absorption of Vitamin B 12), and hormones that regulate digestion. The stomach secretes 66-83 ounces of gastric juice each day!

The acidic environment of the stomach is very important because the food we eat naturally contains microorganisms; the acidity of the stomach helps kill off most of the microorganisms in order to prevent overgrowth of bacteria in the digestive system. The acidity of the stomach is also important because it activates one of the substances that is responsible for digesting proteins.

As the stomach contracts the food you have eaten is churned and mixed with digestive juices to create a mixture called chyme. The stomach slowly releases chyme into the small intestine to be further digested. Look for our next blog to learn about digestion in the small intestine!